Semiconductor processing technology is developing vigorously and going a step further in the nano stage which enhances the development of semiconductor, for example light emitting diodes and semiconductor laser etc. The photo-electronic semiconductors are widely applied to every photo electronic devices such as back light modules, electronic displays, traffic lights, overhand projectors and searchlights. Traditional photo electronic semiconductors are driven by direct current however most of the power supply for cities are using alternating current. The driving circuit for the photo electronics semiconductors has to add an external circuit, which converts the alternating current into the direct current. This means the cost is increased, the process of converting the alternating current to the direct current is affected by the power lost which reduces the operational efficiency of the photo electronics semiconductors thus it is important to develop the technology to apply the direct current for active the photo electronics semiconductors.
Now days the development of the photo electronics semiconductors which uses the AC power supply is distinguish. Many of the countries have disclosed related products or patents in this field, for example the U.S. Pat. No. 6,547,249 “Monolithic Series/Parallel LED Arrays Formed On highly Resistive Substrates” and the U.S. Pat. No. 6,957,89 “Light Emitting Diodes For High AC Voltage Operation and General Lighting” both have revealed that an alternating light emitting diodes modules includes at least two light emitting diode dies, dies of the light emitting diodes take turns to light by the positive and negative waveforms of the alternating currents according to their electrical conduction manners.
To ensure each of the light emitting diodes die is working, each of them has to be electrical independent with each other. In the old time the etching process is used to divide an indentation area between two of the LED dies and the dielectric material forms a dielectric layer on the top of the indentation area, for insulating the electrical conduction between each LED die. The metal coating on the top of dielectric layer is formed by evaporation or sputtering hence the covering of the metal coating is not efficient due to the edge of the metal coating bends too much or directly proportional, this causes the problem of the circuit being turned on or the increase of the resistance.
Taiwan patent number 200812100 “Alternating Current Light emitting device” has proposed a solution as shown in FIG. 1. FIG. 1 shows a prior art for a structure of the light emitting device with an insulate layer. The alternating LED apparatus 10 comprises a substrate 12, at least two dies 14, an insulator 16, a conductive structure 18, a indentation area 142 is formed between two die 14, two sides of two dies 14 is an inclined plane 144, the insulator 16 is formed in the indentation area 142 and attached to the inclined plane 144, conductive structure 18 is on the top of insulator 16 and electrical conducts to the die 14 wherein the die 14 is the LED die. The inclined plane 142 of the die 14 will cause the insulator 16 to loose and slide and the insulation is not efficient. Therefore, the inclined plane 144 of the light emitting device 10 cannot overcome the problem of the insulator 16 loosing and sliding and the insulation of the insulator 16 is not efficient, that will cause the leakage between light emitting units.
Hence, the present invention provides a light emitting device with an insulating layer that the outward appearance of the light emitting unit has a stair structure in order to avoid the insulating layer to slide and loose when it is set up on the light emitting unit thus to avoid the leakage between light emitting units.